As topic..

I stumbled over a bag of Lignite in an old aquarium shop.

What is it for?

Substrate?

activated carbon?

It says only:

Lignite
Watts, Blake, Bearne & Co PLC
Newton, abbot, Devon
UK Origin.

Anyone?

Lignite is immature coal. As for what it's used for, I think I saw an article a while back which suggested using lignite (diamond black or something like that) similar to laterite, under the substrate.

Basically it can be used as yet another 2-layer substrate component?

nothing special?

feels a bit like Aquasoil..

Lignite is Leonadrite. It is recommended as the bottom layer to slow release carbon for bacteria.

Non CO2 methods

I use it in my tanks under different substrates. Old LFS have some great treasures. If its cheap, get it. You'll know what I mean if you've priced Black Diamond.

I've never tried leonardite... or anyother bottom layer substrate.. apart from good old peat, and Tropica's aquacare substrate of course.

I'll keep it in the garage .. :-)